1. Field of the Invention
The present invention relates to a retractable pipe structure of an air blow gun, and more particularly to a retractable pipe which can be adjusted in a stepless way.
2. Description of the Prior Art
As shown in FIG. 6 and FIG. 7, a conventional retractable pipe of an air blow gun comprises an extension pipe 50. One end of the extension pipe 50 is connected to an air blow gun 5. The extension pipe 50 has an end head 51 at the other end thereof. A washer 61 and an O-shaped ring 62 are provided in the end head 51 of the extension pipe 50. The distal end of the end head 51 is provided with an O-shaped ring 63 and connected with a metallic sleeve 70. The sleeve 70 comprises an elastic collet 71 at a front end thereof to connect with a nut 72. A pipe 80 has one end inserted into the extension pipe 50 and passing the washer 61 and the O-shaped ring 62. The distal end of the pipe 80 is connected with a stop ring 81. The pipe 80 is movable in the extension pipe 50 and can be secured by screwing the nut 72, achieving retraction and extension of the pipe 80.
As shown in FIG. 8, the sleeve 70 is made of metal. In particular, the elastic collet 71 must be processed for grooves 73. This causes high cost and is time-consuming. Sometimes, the edges of the grooves 73 have remained iron filings to damage the surface of the pipe 80 during installation.
The elastic collet 71 made of metal is used to clamp the pipe 80. Both the elastic collet 71 and the pipe 80 are made of hard material. When they are contact with each other, the surface of the pipe 80 may have a clamping dent. If the user pulls the pipe 80 carelessly, the elastic collet 71 may scrape the surface of the pipe 80 to leave burrs which may damage the O-shaped ring 62 when retracting the pipe 80. This will cause leakage of compressed air and shorten the service life of the pipe.
The elastic collet made of metal must be processed for the grooves to cause high cost and time waste. The edges of the grooves have remained iron filings to damage the surface of the pipe during installation. Both the elastic collet and the pipe are made of hard material. When they are contact with each other, the surface of the pipe may have a clamping dent to damage the O-shaped ring when retracting the pipe. This will cause leakage of compressed air. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.